Method and device for producing card-like information carriers

ABSTRACT

A method for producing information carriers in the form of cards, in particular credit cards, passes, identification cards, admittance cards etc., the laminating process including placing at least one card template which is to be sized, preferably a laminate consisting of a plurality of sized card layers, into a hollow mold and subjecting it to a simultaneous action of pressure and heat for a predetermined time. The material placed into the hollow mold is heated over at least one large area, as known per se by the use of heating plates, and in the peripheral, narrow, outer boundary region of the inserted material quantities of heat flowing off per se there are retained, blocked in, reflected and concentrated back onto the laminate template.

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/IB99/01560, filedon Aug. 27, 1999. Priority is claimed on that application and on thefollowing application:

Country: Germany, Application No.: 198 39 517.5, Filed: Aug. 29, 1998.

BACKGROUND OF THE INVENTION

Two types of laminators which are suitable for producing plastic cardsconsisting of layers (laminate) by laminating, i.e. bonding together thelayers, are known.

A first group works with oversized laminate layers which are placedbetween two heating plates and are laminated by a conventionallysimultaneous action of heat and pressure. The non-defined boundaries ofthe finished laminate mean that in a second processing step aftercooling said laminate then also has to be cut, namely punched, to thefinal dimensions of the card.

A second group for laminating or heat sealing suitable plastic cardscomprises a hollow mold or cavity which holds the laminate to belaminated and straight away has the final dimensions of the card, andheating plates which are arranged above and below the cavity into which,as is known, cooling bodies are in turn assigned, and alsopressure-exerting means which press the heating plates onto one anotherin such a manner that a laminate held between them is subjected to anappropriately dimensioned action of pressure and temperature for theshort period of action.

A finished card is therefore immediately produced, the laminating alwaystaking place until shortly before or at the softening point of theinserted material to a sufficient extent that an integral, finished cardcan be removed from the cavity.

Laminators of this type from the second group, as are revealed, forexample, in the specifications DE 39 16 708 A1, DE 42 06 342 A1 or EU 0669 214 A1, have a peripheral frame which bounds the receiving cavityand whose internal dimensions correspond to the final dimensions of thecard thereby rendering the subsequent punching processing stepsuperfluous. Laminators of this type which produce a finished, sizedcard and which are also referred to in the following as sizinglaminators, generally also have a pressure-compensating body so as toensure a uniform surface structure of the finished card and, inparticular, also a uniform action of pressure during the laminatingprocess.

However, the fact that the borders of the inserted laminate layersnecessarily bear against the sized mold parts during the laminatingprocess and therefore a loss of heat inevitably also occurs in theseregions, so that although a uniform action of pressure can be spoken of,this type of heat sealing, i.e. laminating, does not succeed in alsoensuring a uniform action of heat in all regions of the insertedmaterial which is to be laminated, may be problematical in sizinglaminators of this type.

The reason for this resides in the fact that only the heating plates onboth sides have final dimensions, with the result that, when viewedpurely physically, said heating plates necessarily already have acertain temperature gradient from the center to the boundary regions.However, this problem could be countered by an appropriately suitabledistribution of the heating means—but what cannot be rectified in thismanner, particularly if the shortness of the laminating time over whichthe action of pressure and temperature is maintained on the insertedlaminate is included, is the fact that the boundary regions of theinserted material which is to be laminated which are pressed against thelateral, sized mold parts or come to bear against the latter lose heatin this region, with the result that the uniform distribution of theacting quantities of heat which is required over the entire surface ofthe laminate for a uniform laminating process cannot be ensured.

This means that the laminating possibly, or even with some degree ofprobability, does not take place completely, especially in the boundaryregion of the card, with the result that the layers which are to bebonded together may be broken open again from that point, for examplefor forgery purposes. This circumstance can also not be countered bysimply heating more intensively overall, since this leads to excessiveheating of the laminate in the central region, with the result that anundesirable fusing together of the material and possibly even of anyinformation, data and the like which is present could occur. Such ameasure would also not be conducive for inserted electronic parts.

SUMMARY OF THE INVENTION

The invention is therefore based on the object of providing a remedy forthis and also of ensuring a uniform laminating process including theboundary regions of the card in such laminators which are sized by wayof their mold parts.

The method according to the invention achieves this object by avoidingthe discharge of heat energy in the boundary regions of the cavity ofthe laminator or, which is synonymous therewith, by maintaining and, asit were, concentrating the heat back through the mold onto the insertedcard which is to be laminated or onto the laminate, it is ensured thatsaid mold reaches the precise softening temperature required for thelaminating process in the boundary regions at the same time as in thecentral region. This not only results in an elegant appearance of theentire finished product over its entire surface, but also in thecertainty that the layers of the laminate which are to be laminated toone another are also satisfactorily connected to one another especiallyin the boundary region and that when an individual layer is inserted,the boundary region thereof obtains the same degree of lamination as thecentral region.

Such a result can be achieved in differing ways, for example by the moldhaving a peripheral, preferably also completely closed, frame made of asuitable material which conducts heat with difficulty or poorly, wherethe frame simultaneously forms, by means of its internal dimensions, themold cavity for the laminate to be received. Such a frame may, forexample, consist of a plastic which conducts heat poorly or very poorly,for example glass fiber reinforced epoxy resin; however, it may alsohave a suitable sandwich construction having an internal coating whichconducts heat with difficulty, or it may consist entirely, for example,of a material, such as ceramic or other insulator material.

Appropriately designing the upper and outer heating plates to includethe heat-deflecting properties of the frame of a sizing laminator ofthis type then enables the inserted laminate to be uniformly andcompletely laminated over its entire surface and therefore including itsboundary regions.

BRIEF DESCRIPTION OF THE DRAWING

The drawing shows in a cross-sectional diagram one possible constructionof a laminator together with inserted card components and aheat-insulating mold frame.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The basic concept of the present invention resides in designing thecavity of a sizing laminator in such a manner that during the laminatingprocess, i.e., for example, during the bonding together of a pluralityof inserted card laminate layers or the laminating of an individual,thick plastic layer, the boundary regions of the card manufactured tothis extent to size are able to make full use for the laminating processof the heat energy supplied to the heating plates, i.e. heat isprevented from being discharged via the boundary regions and the moldparts which are necessarily present there and are used as a bearing. Forthis purpose, a material which conducts heat very poorly is preferablyprovided for a frame forming the boundaries of the cavity, with theresult that the quantity of heat which is supplied remains within thecavity and a satisfactory laminating process of the inserted material(laminate) is ensured at all locations.

In the attached drawing, the sizing laminator is denoted by 12 andcomprises an upper heating plate 2 and a lower heating plate 6 which, inconjunction with a frame 7, form a cavity which is used for holding thematerial to be laminated.

This material to be laminated usually concerns ready-sized card layers,preferably PVC layers, for a card to be laminated, which layers form alaminate and are therefore inserted as a stack comprising the layers 3,4 and 5 into the hollowed space of the mold, i.e. the cavity of thelaminator.

It can furthermore be seen that in order to apply the required pressurein the case of the exemplary embodiment illustrated in the drawing of alaminator 12, the lower heating plate 6 corresponds with the greatestpossible accuracy to the internal dimensions of the frame 7 andtherefore also to the final dimensions of the card which is to beproduced, with the result that this heating plate can be inserted, frombelow in this case, into the cavity 7 a which is formed by the hollowspace of the frame 7.

Since, in order to carry out a correct laminating process, i.e.initially rapid feeding in of the required quantities of heat underpressure for the laminating process and then just as rapid dissipationof the heat so that the product which is produced can be removed insolid form from the laminator, the two heating plates 2 and 6 bearcooling bodies 1 and 8 on the side which faces away from the cavity, thelower cooling body 8 here also has approximately the dimensions of thecard in order likewise to be able to be inserted into the cavity.

In the exemplary embodiment illustrated, the pressure required for thelaminating process is applied via the lower heating plate 6 inconjunction with the feeding in of heat, with the result thatappropriate, pressure-producing means, indicated in the drawing as aprestressing spring 9 representing all other options, act on the lowercooling body 8.

The upper cooling body 2 overlaps the frame 7 preferably on all sides byway of a lip 2 a projecting all around, with the result that it rests,as it were, as a lid on the frame 7, in which case, with stationarypositioning of the upper heating plate 2 together with the assignedcooling body 1, the frame 7 can be mounted in a moveable manner and ispressed by dedicated prestressing means 10 by an appropriate pressurefrom below against the upper heating plate 2. This firm bearing andboundary-side overlapping of the frame structure by the cooling-body lip2 a ensure that at least on the upper surface of the finished card asatisfactory, also visually attractive lamination is obtained togetherwith a precise boundary edge for the card which is produced to size. Ofcourse, in this completed version this is not possible for the lowerboundary-edge corner region of the card, since the laminating pressurehas to be applied and, for this purpose, the lower heating plate 6 hasto have a clearance, even if only very slight, from the insidedimensions of the frame in order to enable it to be able to be movedrelative to the frame 7.

The frame 7 itself consists of a material which conducts heat onlyslightly or only very slightly or is provided, at least on its innersurface, i.e. on the regions facing the laminate to be laminated, with acoating which conducts heat with appropriate difficulty. For betterunderstanding, in the graphical illustration the inserted laminate ofthe card which consists of the three layers 3, 4 and 5 is illustratedexcessively thickly; however, in every case the material flows and fusestogether, with the result that the hollow space of the mold or thecavity of the laminator is completely filled by the card material or thelaminate during the laminating process.

The frame characteristics of conducting heat poorly, deflecting heat,reflecting heat and of concentrating the quantity of heat transferredfrom the heating bodies to the inserted laminate back onto the laminatemeans that during the laminating process, which is actually usuallyfinished in seconds, there is no significant transfer of heat energyfrom the cavity or by the laminate material or card material to theinner sized mold wall of the frame 7, with the result that uniformheating and uniform bonding, i.e. laminating, of all of the layers ofthe card is ensured with a satisfactory, external appearance also beingobtained.

As the drawing illustrates, in the overlapping region of the upperheating plate 2 the frame 7 can have a peripheral incision or anexternal recess 7 b by means of which the frame mass is clearly smallerat the point where the laminating process takes place after the insertedlaminate has been compressed, with the result that, for example, theheat absorption of the frame is thereby also reduced, in addition to itsheat-deflecting, reflecting or heat-insulating characteristics.

However, the main reason for this reduction in material is the increaseobtained by this means in the specific pressure exerted by theprestressing means 10 between the upper heating plate and the upperframe boundary edge, which abuts from below against the heating plate,at given pressure values. Particularly good sealing of the cavity atthis location and a clean, highly precise mold border are obtained inthis manner. This is of importance for the fusing together of thelaminate material which takes place in this region, resulting here in aclean, cut-like boundary-edge transition for the finished edge. It istherefore also recommended to grind the edge transition finely in asimilar manner to a flat piston ring.

Furthermore, it may be expedient to select for the prestressing means 10for the frame a support against the lower cooling body, since the higherthe pressure which is exerted by the heating plates, the higher theframe pressure (against the upper heating plate) also has to be so as toavoid the material fusing together in the transitional boundary-edgeregion.

Thus, while there have been shown and described and pointed outfundamental novel features of the present invention as applied to apreferred embodiment thereof, it will be understood that variousomissions and substitutions and changes in the form and details of thedevices illustrated, and in their operation, may be made by thoseskilled in the art without departing from the spirit of the presentinvention. For example, it is expressly intended that all combinationsof those elements and/or method steps which perform substantially thesame function in substantially the same way to achieve the same resultsare within the scope of the invention. Substitutions of elements fromone described embodiment to another are also fully intended andcontemplated. It is also to be understood that the drawings are notnecessarily drawn to scale but that they are merely conceptual innature. It is the intention, therefore, to be limited only as indicatedby the scope of the claims appended hereto.

1. A method for producing a card-shaped information carrier, comprisingthe steps of: placing at least one card template which is to be sizedinto a hollow mold; subjecting the template to a simultaneous action ofpressure and heat for a predetermined time so that the template placedinto the hollow mold is heated over at least one large area by heatingplates; and enclosing a peripheral, narrow, outer boundary region of theinserted template with a peripheral frame consisting of a material whichis one of substantially non-heat-conducting and reflects heat and alsoconcentrates heat back onto an inserted laminate, the frame havinginternal dimensions that correspond to final dimensions of thecard-shaped carrier, so that quantities of heat flowing off per se thereare retained, blocked in, reflected and concentrated back onto thetemplate, wherein the enclosing step includes enclosing the peripheral,narrow, outer boundary region of the inserted template with a peripheralframe having a reduction in material in a transitional edge region inorder to increase specific contact pressure between a frame border edgeand the upper heating plate.
 2. An apparatus for producing a sized,card-shaped information carrier comprising a frame defining a cavity inwhich card layers are placeable for lamination by pressure and heat, aperipheral region of the frame consisting of a material which is one ofsubstantially non-heat-conducting, reflects heat and concentrates heatback onto an inserted laminate, the frame having internal dimensionsthat correspond to final dimensions of the card-shaped carrier, andfurther comprising heating plates arranged on both sides of the frameforming, by its internal dimensions, the cavity for the laminatingprocess, the heating plates including an upper heating plate and a lowerheating plate, the frame having a reduction in material in atransitional edge region in order to increase specific contact pressurebetween frame border edge and the upper heating plate, one of theheating plates having external dimensions that correspond to theinternal dimensions of the frame and being insertable with aprestressing action into said frame so as to produce the pressurerequired for laminating.
 3. An apparatus as defined in claim 2, whereinthe lower heating plate has the external dimensions that correspond tothe internal dimensions of the frame, and further comprising a coolingbody adjacent to the lower heating plate so that the cooling body isinsertable together with the lower heating plate into the frame.
 4. Anapparatus as defined in claim 3, and further comprising prestressingmeans for prestressingly acting on the cooling body adjacent to thelower heating plate.
 5. An apparatus as defined in claim 3, wherein theupper heating plate is arranged to close the cavity formed by the framein a lid-like manner by way of a boundary lip projecting over the framedimensions.
 6. An apparatus as defined in claim 5, and furthercomprising pressure-producing means for pressing the frame and the upperheating plate firmly against one another so that between the upperheating plate, which closes the cavity in a lid-like manner, and theframe an intrinsic relative movement is possible.
 7. An apparatus asdefined in claim 5, and further comprising dedicated prestressing meansfor pressing a transitional boundary edge of the frame against theboundary lip of the upper heating plate.
 8. An apparatus as defined inclaim 7, wherein the frame prestressing means are supported on thecooling body which is assigned to the lower heating plate and subjectsthe lower heating plate to pressure.
 9. An apparatus as defined in claim2, wherein the reduction in material is formed by a peripheral, outerannular recess in the frame.